I think part of what might have been going on here had to do with the depth.
I know that when I'm diving in Egypt with my regular buddy we dive shallow a lot (15m is not uncommon) and we maintain less strict buddy contact than during our "normal" dives together.
On our normal dives we're diving to depths of 50m, we're over the NDLs (sometime *well* over), we're both carrying 3 or 4 tanks, it's cold, it's dark, the margins for error or more limited and we dive like... well... like our lives depend on good buddy contact.... as it does.
On vacation in Egypt, we would only do this on a relatively deep dive or a dive over the NDLs. Frankly we don't dive (often) over the NDL's on vacation because of making so many repetitive dives. The context is a LOT different than our "normal" dives and frankly, it seems a LOT easier.
So we may agree to be separated by 10m or so. One reason we might decide to do that is if we're looking for a specific critter. One of the things we pride ourselves on while on vacation is that if we say "we're looking for critter X on this dive", that we can usually find it. (aside from things like dolphins or whale sharks, that have their own agendas).
But for example, we may spend an entire dive looking for an octopus. They're not always easy to find but we can usually find them... but not if we're joined at the shoulder. To the untrained observer it may look like we aren't "tight", as in this video.
In our case, I can assure you if something happened to either of us, the gap of 10m would be closed very quickly. In the case of the diver in the video, I see someone who needs to learn a few things but may be suffering from the same mindset myself and my buddy do in the tropics.....
Thinking that since the diving is so easy and so shallow, "what could possibly go wrong".
Food for thought?
R..
